To Harvard professor Clayton Christensen, coauthor of How Will You Measure Your Life?, a primary task of leadership is asking questions that anticipate great challenges.

This is the second interview we’ve published with Harvard Business School professor and author Clayton Christensen. The first appeared back in 2001. Four years before, Christensen had published The Innovator’s Dilemma: When New Technologies Cause Great Firms to Fail (Harvard Business School Press, 1997). When his keenly original theory of disruption first appeared, it seemed like an audacious and counterintuitive view of organizational change. But it soon evolved into conventional business wisdom. And now he is applying it to a deeper question: What is life for?

In The Innovator’s Dilemma, Christensen argued that as companies focus their attention on their best and most reliable customers, they can all too easily overlook the threat of disruption from young upstart competitors. Those competitors, exercising their creativity, develop innovative capabilities and reach customers that the incumbents ignore. Sooner or later, the upstarts steal the market with their better, less-expensive new ways of solving customers’ problems.

Christensen has always had an entrepreneurial bent, and this clearly colors his approach. Before arriving at Harvard Business School, he founded the CPS Technologies Corporation, a manufacturer of thermal management materials (originally called the Ceramics Process Systems Corporation), and he is a cofounder of a small Boston-based consulting firm called Innosight. His ideas are particularly valuable for established industries that seek to respond effectively to the disruption coming seemingly out of nowhere. In recent years, he has applied this approach to healthcare (The Innovator’s Prescription: A Disruptive Solution for Health Care, with Jerome H. Grossman and Jason Hwang, McGraw-Hill, 2008), education (Disrupting Class: How Disruptive Innovation Will Change the Way the World Learns, with Michael Horn and Curtis W. Johnson, McGraw-Hill, 2008), and, most recently, the personal side of leadership.

Written as a reflection on the fulfillment of life’s purpose after a series of severe medical problems (including cancer and a stroke), Christensen’s most recent book, How Will You Measure Your Life? (coauthored with James Allworth and Karen Dillon, HarperBusiness, 2012), has struck a chord with many business leaders. It links the discipline of managing disruption to the kind of long-term thinking that is necessary if one is to step past today’s pressures and build a strong personal and professional legacy. In late 2012, Christensen spoke with strategy+business by phone from his home outside Boston.

S+B: How did you develop the concept of measuring your life?CHRISTENSEN: I had always aspired as a researcher to develop models that were robust enough to relate to any level in a hierarchy, from a national economy to an industry to a corporation to a business unit to a team. A good theory is really a fundamental statement of causality, and it ought to be as applicable to a business unit as it is to a nation, or vice versa.

In all my work, I’ve looked for universal principles—starting with my doctoral thesis in the early 1990s, which was the original study of disruption in the disk drive industry [which I wrote about in The Innovator’s Dilemma]. I was trying to explain why it was so hard for successful disk drive companies to sustain their success, generation after generation. I’d concluded that the success of their past practices made it difficult to react effectively to new disruptive competitors.

At first, when I finished, I thought I had a model that applied only to the disk drive industry. Then I remembered that during the Cuban missile crisis, which had happened when I was a boy in 1962, my neighbors hired a steam shovel to dig a bomb shelter in their basement. The steam shovel was manufactured by Northwest Engineering, a company that died in the early 1980s because its products were made obsolete by hydraulic excavators. So, later, when I knew someone who worked for an excavating company, I went over to see him one night and described what I’d found in the disk drive industry, and he said the same thing had happened with big digging machines. “There must be something to this,” I thought, “if it explains hydraulic excavators and disk drives.”

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